/* Filename:  templat3.cpp

   Programmer:  Br. David Carlson

   Date:  June 28, 1998

   Last Revised:  December 23, 2001

   This program prompts the user to enter a sequence of integers and prints
   prints them in reverse order.  Then it prompts the user to enter a
   sequence of characters and prints them in reverse order.  A template-
   based array implementation of a stack is used.

   Tested with:
      Microsoft Visual C++ 2019
*/

#include <iostream>
using namespace std;


const int StackMax = 200;   // our stacks can only hold this many items


template <class T> class ArrStackClass
   {
   public:
      ArrStackClass(void);
      bool Empty(void) const;
      void Push(const T & Item);
      void Pop(T & Item);
   private:
      int Top;
      T Info[StackMax];
   };


/* Given:  Nothing.
   Task:   This is a constructor. It creates and initializes a new stack
           to empty.
   Return: Nothing other than the newly created object.
*/
template <class T> ArrStackClass<T>::ArrStackClass(void)
   {
   Top = -1;
   }


/* Given:  Nothing (other than the implicit ArrStackClass object).
   Task:   To check whether this object is empty.
   Return: true if it is empty, false otherwise.
*/
template <class T> bool ArrStackClass<T>::Empty(void) const
   {
   if (Top < 0)
      return true;
   else
      return false;
   }


/* Given:  Item   A data item.
   Task:   To push item onto the stack (the implicit object).
   Return: Nothing directly, but the implicit object is modified.
*/
template <class T> void ArrStackClass<T>::Push(const T & Item)
   {
   Top++;
   if (Top == StackMax)
      {
      cerr << "Error:  no room to push an item onto the stack" << endl;
      exit(1);
      }
   else
      Info[Top] = Item;  // assumes = works for type T
   }


/* Given:  Nothing.
   Task:   To pop the top item from the stack (the implicit object).
   Return: Item   The item popped from the stack.
*/
template <class T> void ArrStackClass<T>::Pop(T & Item)
   {
   if (Top < 0)
      {
      cerr << "Error:  cannot pop an item from an empty stack" << endl;
      exit(1);
      }
   else
      {
      Item = Info[Top];   // assumes that = works for type T
      Top--;
      }
   }


int main(void)
   {
   ArrStackClass<int> IntStack;
   ArrStackClass<char> CharStack;
   int Number;
   char Ch;

   cout << "Enter an integer (0 to quit): ";
   cin >> Number;

   while (Number != 0)
      {
      IntStack.Push(Number);
      cout << "Enter another integer (0 to quit): ";
      cin >> Number;
      }

   if (IntStack.Empty())
      cout << endl << endl << "Stack is empty" << endl;
   else
      {
      cout << endl << endl << "Numbers in reverse order are:" << endl;
      while (! IntStack.Empty())
         {
         IntStack.Pop(Number);
         cout << Number << endl;
         }
      }

   cin.clear();
   cout << endl << "Enter a character (q to quit): ";
   cin >> Ch;

   while (Ch != 'q')
      {
      CharStack.Push(Ch);
      cout << "Enter another character (q to quit): ";
      cin >> Ch;
      }

   if (CharStack.Empty())
      cout << endl << endl << "Stack is empty" << endl;
   else
      {
      cout << endl << endl << "Characters in reverse order are:" << endl;
      while (! CharStack.Empty())
         {
         CharStack.Pop(Ch);
         cout << Ch << endl;
         }
      }

   return 0;
   }